From the Blaupunkt catalog, “Sound und Fahrvergnüfgen pur.(Sound and Driving Pleasure to the Max). Mobile Kommunikation von Blaupunkt (Mobile Communication from Blaupunkt). Programm (Program) '96/'97”, for example, compact disk changer CDC-FO5 is referred to, on which digital audio data stored on a compact disk may be played back on a playback device.